1. Field of the Invention
The embodiments of the invention generally relate to microelectromechanical systems (MEMS) devices and microelectronic devices, and, more particularly, to Lorentz force magnetometer devices.
2. Description of the Related Art
Conventional MEMS Lorentz force magnetometer designs, such as those described in U.S. Pat. No. 5,959,452, issued to Givens et al. on Sep. 28, 1999, the complete disclosure of which is herein incorporated by reference, describe both optical and capacitive transduction schemes. This capacitive design has achieved a sensor resolution of approximately 1 μT using a drive current of 1 mA and a Q-factor of 20,000, such as suggested by Wickenden et. al, “An Extremely Sensitive MEMS Magnetometer for use as an Orientation Sensor on Projectiles,” Royal Aeronautical Society Conference, Nanotechnology and Microengineering for Future Guided Weapons, Nov. 11, 1999, the complete disclosure of which is herein incorporated by reference.
However, producing miniaturized optical MEMS devices, such as magnetometers, generally appears to present substantial technical challenges including overcoming size, weight, and power consumption parameters as well as attaining acceptable sensor resolution standards. In addition, the proposed piezoelectric devices appear to suffer from inappropriate design choices. Using the same electrode for driving the Lorentz force current and piezoelectrically sensing those Lorentz forces directly couples the drive and sense functions of the sensor; which generally prevents the measurement of external magnetic fields. This may also severely limit the maximum drive currents of the device due to the limited cross-sectional area and thermal/electrical material properties of the chosen conductor, platinum. Generally, the limited drive current directly limits the sensitivity and resolution of such a device.
Accordingly, there remains a need for a novel MEMS magnetometer device capable of mapping magnetic fields in various applications, and which is further capable of achieving size, weight, power consumption, and resolution parameters previously unattainable by the conventional designs.